Anthrapyridone compound, water-based magenta ink composition, and method of ink-jet recording

ABSTRACT

An object of the present invention is to provide a water-based magenta ink composition which has a hue and clarity suitable for ink-jet recording and gives prints excellent in fastnesses such as an ozone resistance and a light resistance.  
     The ink composition comprises as its coloring matter component a water-based magenta composition containing anthrapyridone compound represented by the formula (1):  
                 
 
     wherein R represents hydrogen atom or methyl group; X represents phenyl group, phenoxy group or halogen atom; and n is an integer of 1 to 4,  
     or a salt thereof.

FIELD OF THE INVENTION

[0001] The present invention relates to a novel sulfonic acid derivativeof anthrapyridone compound or its salt, a water-based magenta inkcomposition for ink-jet recording comprising said compound, and anink-jet recording method using said composition.

BACKGROUND OF THE INVENTION

[0002] As a recording method using an ink-jet printer, various kinds ofdiverse ink jetting systems have been developed, and for recording inthese systems, ink droplets are generated and deposited to variousrecording materials (paper, film, cloth etc.).

[0003] A recording method via an ink-jet printer has characteristicssuch that no sound is produced since there is no contact between arecording head and a recording material and this method can print on avariety of substrates such as a substrate having uneven surfaces, asubstrate comprising a soft material, and a fragile substrate. Recently,ink-jet printers are spread rapidly since it is easy to reduce theirsize, to print with a high speed and to make color prints. They areexpected to be further popularized significantly.

[0004] In order to record in color picture or character informations ona color display of a computer via an ink-jet printer, a subtractivemixture method with four inks comprising three primary coloring mattersof yellow (Y), magenta (M) and cyan (C) and additionally black (K) isgenerally adopted. To reproduce a subtractive mixed color image asfaithfully as possible by a subtractive mixed color image of red (R),green (G) and blue (B) for CRT displays etc., it is desired thatcoloring matters used, particularly coloring matters used in YMC inks,have hues as near as possible to standard hues of YMC and are as vividas possible. And, an ink composition is requested to be stable for along-period storage and to give prints having a high concentration andexcellent in fastnesses such as water resistance, light resistance, andozone resistance. Prints resulting from recording via an ink-jet printerwill be applied for display such as advertisement in order to broaden anapplication of an ink composition. In such cases, prints will be oftenexposed to light (an electric lamp, a fluorescent lamp, a sunlight andthe like) and an air (containing nitrogen oxide gas, ozone gas and thelike). Thus, an ink composition giving printed images excellent in ozoneresistance is especially requested. Many images printed on coated papersvia an ink-jet printer are faded by ozone. Reason considered is aninteraction between an ozone gas in an air and inorganic substancesand/or polymers applied on coated papers, but it is not correctlyelucidated at present. The present invention relates to a magenta inkamong inks having the above hues.

[0005] The application of ink-jet printers is broadened from smallprinters for OA to large printers for industry, and a chance to exposeprints outdoors is increasing. Thus, the improvement of fastnesses suchas water resistance, light resistance, and ozone resistance is furtherrequested. Among these properties, water resistance is under significantimprovement by coating, together with PVA resin, organic or inorganicfine particles (e.g. cationic polymer, porous silica, alumina sol andspecial ceramics) capable of adsorbing coloring matters in ink, onto thesurface of the paper. In practice, such papers have been commerciallyavailable as various coated papers for ink-jet printing. However, atechnique significantly improving light resistance and ozone resistancehas not been established yet. If prints resulting from printing oncoated papers called as glossy papers are left in a well ventilatedplace, they are faded and discolored. In order to resolve this problem,prints are processed by laminating after printing so as to prevent themfrom fading at present. However, this method has many demerits in time,convenience and cost. To provide a fundamental method for improving theabove problem, the development of a magenta dye which is hardly faded isan important problem.

[0006] Representative skeletons of a magenta coloring matter used in awater-based ink for ink-jet recording are xanthene as described inJP-A-54089811 (1979), JP-A-08060053 (1996), JP-A-08143798 (1996) and thelike; and azo having H acid in its skeleton as described inJP-A-61062562 (1986), JP-A-62156168 (1987), JP-A-03203970 (1991),JP-A-07157698 (1995), JP-B-07078190 (1995) and the like. However,xanthene coloring matter have very poor light resistance although theyare very excellent in hue and clarity. While, azo coloring matter havingH acids in their skeletons have poor light resistance and clarityalthough they have good hue and water resistance. As described inJP-A-03203970 (1991), an azo magenta dye excellent in clarity and lightresistance has been developed, but its light resistance is stillinsufficient as compared with dyes having other hues such as a cyan dye,a representative of which is a cupper phthalocyanine dye, a yellow dyeand the like. And, prints resulting from printing with these coloringmatters on glossy papers may be discolored and faded even if they areleft in a well ventilated place.

[0007] Further, as a magenta coloring matter excellent in clarity andlight resistance, coloring matters having anthrapyridone skeleton asdescribed in JP-A-59074173 (1984), JP-A-02016171 (1990) and the like areknown, but they do not meet all requirements of hue, clarity, lightresistance, water resistance, ozone resistance and a solution stability.

[0008] An object of the present invention is to provide a water-basedmagenta ink composition having a hue and clarity suitable for ink-jetrecording and gives prints excellent in fastnesses such as a lightresistance, and an ozone resistance.

SUMMARY OF THE INVENTION

[0009] The present inventors hardly researched for resolving the aboveproblems. As the result, the present invention was completed. That is,the present invention relates to:

[0010] (1) an anthrapyridone compound represented by the formula (1):

[0011] wherein R represents hydrogen atom or methyl group; X representsphenyl group, phenoxy group or halogen atom; and n is an integer of 1 to4,

[0012] or a salt thereof;

[0013] (2) the anthrapyridone compound as described in (1) wherein n isan integer of 2 to 4, or the salt thereof;

[0014] (3) the anthrapyridone compound as described in (2) wherein Xrepresents phenyl group, or the salt thereof;

[0015] (4) an anthrapyridone compound represented by the formula (2):

[0016]  wherein X represents phenyl group, phenoxy group or halogenatom, or a salt thereof;

[0017] (5) an anthrapyridone compound represented by the formula (3):

[0018]  wherein X represents phenyl group, phenoxy group or halogenatom, or a salt thereof;

[0019] (6) an anthrapyridone compound represented by the formula (4):

[0020]  or a salt thereof;

[0021] (7) a water-based magenta ink composition comprisinganthrapyridone compound as described in any one of (1) to (6) or a saltthereof;

[0022] (8) a water-based magenta ink composition as described in (7)comprising water and a water-soluble organic solvent;

[0023] (9) a water-based magenta ink composition as described in (7) or(8), wherein said composition is for ink-jet recording;

[0024] (10) an ink-jet recording method, which comprises using thewater-based magenta ink composition as described in any one of (7) to(9) as the ink in the ink-jet recording way that ink droplets are jettedresponding to recording signal to record on a recording material;

[0025] (11) an ink-jet recording method, which comprises using thewater-based magenta ink composition as described in any one of (7) to(9) as the ink and a water-based cyan ink composition comprising awater-soluble metal phthalocyanine coloring matter as a cyan ink in theink-jet recording way that ink droplets are jetted responding torecording signal to record on a recording material;

[0026] (12) an ink-jet recording method as described in (10) or (11)wherein the substrate to be recorded is a polyamide fibrous material andthe fibrous material is heat treated after the ink composition isapplied;

[0027] (13) an ink-jet recording method as described in (10) or (11)wherein the recording material is an information transmittance sheet;

[0028] (14) an ink-jet recording method as described in (13) wherein theinformation transmittance sheet is a surface treated sheet;

[0029] (15) an ink-jet printer in which a container containing awater-based magenta ink composition as defined in any one of (7) to (9)and a container containing a water-based cyan ink composition comprisinga water-soluble metal phthalocyanine coloring matter are set.

DETAILED DESCRIPTION OF THE INVENTION

[0030] The present invention will be described in more detail.

[0031] The anthrapyridone compound of the formula (1) is obtained by,for example, the following method. That is, to 1 mole of the compoundrepresented by the formula (6):

[0032] is added ethyl benzoylacetate generally in an amount of 1 to 3moles and then they are heated in a solvent such as xylene in thepresence of a catalytic amount of sodium carbonate or sodium carbonateanhydride at a temperature of generally 130 to 145° C. for a period ofgenerally 2 to 10 hours, while water and ethanol produced are removed byazeotropic distillation with the solvent so that a ring closure iseffected, thereby the compound of the formula (7):

[0033] is obtained. Then, this compound of the formula (7) is added tofuming sulfuric acid having a concentration of generally 5 to 30% andsulfonated at a temperature of generally 5 to 100° C. for a period ofgenerally 15 minutes to 10 hours, thereby the anthrapyridone compound ofthe formula (1) is obtained.

[0034] The novel anthrapyridone compound of the present invention isrepresented by the formula (1). Example of the substituent X on phenoxygroup in the formula (1) includes p-phenyl, o-phenyl, p-phenoxy,p-chloro, o-chloro, p-bromo groups and the like.

[0035] Examples of the compound represented by the formula (2) of thepresent invention are set forth below:

[0036] The present compound may be in the form of a free acid or a salt.The sulfonated product of the compound of the formula (2) can be used asa free acid or a salt such as an alkali metal salt, an alkaline earthmetal salt, an alkylamine salt, an alkanolamine salt and an ammoniumsalt. Example of the preferable salt includes alkali metal salts such assodium, potassium and lithium salts; ammonium salt; and alkanolaminesalts such as monoethanolamine, diethanolamine, triethanolamine,monoisopropanolamine, diisopropanolamine and triisopropanolamine salts.

[0037] A salt of the sulfonated product of the compound of the formula(2) is prepared by, for example, the following method.

[0038] First, a sufonated reaction liquid is added into an iced water,to which sodium chloride is added to salt out and the reaction productis filtered, thereby a sodium salt of the sulfonated product of thecompound of the formula (2) is obtained. Then, this sodium salt isdissolved in water and an acid is added to precipitate crystals. Thecrystals are filtered to obtain a coloring matter in a free acid form asa cake. Then, the coloring matter in a free acid form is dissolved orsuspended in water, in which the amine or metal salt mentioned above isadded and dissolved, thereby a desired salt of the sulfonated product ofthe compound of the formula (2) is obtained.

[0039] The water-based ink composition of the present invention isobtained by dissolving the above coloring matter component in water, oroptionally mixture of water and water-soluble organic solvent. A pH ofthe resultant ink is preferably about 6 to 10. When the water-based inkcomposition is used in an ink-jet printer, the coloring mattercontaining a minor amount of inorganic substances such as chloride,sulfate and the like of metallic cations is preferably used. As acriterion of a total amount of inorganic substances, a total amount ofsodium chloride and sodium sulfate of at most 1% by mass may bementioned. In order to prepare the coloring matter component containinga minor amount of inorganic substances of the present invention, thecoloring matter component of the present invention may be desaltedaccording to a routine method using a reverse osmosis membrane, a methodcomprising dissolving the coloring matter component in the form of a dryproduct or a wet cake in a mixture of alcohol and water with stirring,filtering and drying, or the like.

[0040] The water-based ink composition of the present invention isformulated as a composition based on water. The coloring mattercomponent of the present invention is contained in an amount ofpreferably about 0.1 to 20% by mass, more preferably about 1 to 10% bymass, even more preferably about 2 to 8% by mass in the water-based inkcomposition. Further, the water-based ink composition of the presentinvention may comprise 0 to 30% by mass of a water-soluble organicsolvent and 0 to 5% by mass of ink additives.

[0041] The ink composition of the present invention is prepared byadding and mixing the above compound of the present invention andoptionally a water-soluble organic solvent, ink additives or the like inwater free from impurities such as a distilled water and the like.Alternatively, the compound of the present invention may be added anddissolved in a mixture of water, a water-soluble organic solvent, inkadditives and the like. If necessary, impurities may be removed byfiltering after the ink composition is prepared.

[0042] Example of the usable water-soluble organic solvent includesC1-C4 alkanols such as methanol, ethanol, propanol, isopropanol,butanol, isobutanol, sec-butanol, and tert-butanol; carboxamides such asN,N-dimethylformamide and N,N-dimethylacetamide; lactams such asN-methylpyrrolidin-2-one; cyclic ureas such as1,3-dimethylimidazolidin-2-one and 1,3-dimethylhexahydro pyrimid-2-one;ketones or ketoalcohols such as acetone, methyl ethyl ketone, and2-methyl-2-hydroxypentan-4-one; ethers such as tetrahydrofuran anddioxane; mono-, oligo- or poly-alkylene glycols or thioglycols havingC2-C6 alkylene units such as ethylene glycol, 1,2- or 1,3-propyleneglycol, 1,2- or 1,4-butylene glycol, 1,6-hexylene glycol, diethyleneglycol, triethylene glycol, dipropylene glycol, thiodiglycol,polyethylene glycol, and polypropylene glycol; polyols (triols) such asglycerol and hexane-1,2,6-triol; C1-C4 alkyl ethers of polyhydricalcohols such as ethylene glycol monomethyl ether, ethylene glycolmonoethyl ether, diethylene glycol monomethyl ether, diethylene glycolmonoethyl ether, triethylene glycol monomethyl ether, and triethyleneglycol monoethyl ether; γ-butyrolactone; dimethyl sulfoxide; and thelike. The water-soluble organic solvent may be used in mixture.

[0043] Effective water-soluble organic solvent includesN-methylpyrrolidin-2-on and mono-, di- or tri-alkylene glycol havingC2-C6 alkylene units, preferably mono-, di- or tri-ethylene glycol,dipropylene glycol, dimethyl sulfoxide and the like,N-methylpyrrolidin-2-on, diethylene glycol and dimethyl sulfoxide areespecially preferably used.

[0044] Example of ink additives includes an antiseptic andmildew-proofing agent, a pH controlling agent, a chelating agent, a rustpreventive, a water-soluble UV absorber, a water-soluble polymericcompound, a dye solubilizing agent, a surfactant and the like. Exampleof an antiseptic and mildew-proofing agent includes sodiumdehydroacetate, sodium sorbate, sodium 2-pyridinethiol-1-oxide, sodiumbenzoate, sodium pentachlorophenol and the like. As a pH controllingagent, any compound can be used as long as it does not affect an inkcomposition to be formulated and it can control a pH of an inkcomposition in the range of 6 to 11. Example thereof includesalkanolamines such as diethanolamine, and triethanolamine; alkali metalhydroxides such as lithium hydroxide, sodium hydroxide, and potassiumhydroxide; ammonium hydroxide; alkali metal carbonates such as lithiumcarbonate, sodium carbonate, and potassium carbonate; and the like.Example of a chelating agent includes sodium ethylendiaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylendiamine triacetate, sodium diethylene triaminepentacetate, sodiumuramildiacetate and the like. Example of a rust preventive includes acidsulfite, sodium thiosulfate, ammonium thioglycolate, diisopropylammoniumnitrite, pentaerythritol tetranitrate, dicyclohexylammonium nitrite andthe like. Example of a water-soluble polymeric compound includespolyvinyl alcohol, a cellulose derivative, polyamine, polyimine and thelike. Example of a water-soluble UV absorber includes sulfonatedbenzophenone, sulfonated benzotriazole and the like. Example of a dyesolubilizing agent includes ε-caprolactam, ethylene carbonate, urea andthe like. Example of a surfactant includes known surfactants of anionic,cationic or nonionic type.

[0045] Example of a recording material applicable to the ink-jetrecording method of the present invention includes informationtransmission sheet such as papers and films, fibers, leathers and thelike. Preferable information transmission sheets are surface treatedsheets, specifically sheets having ink receiving layers on the abovesubstrates. The ink receiving layer is provided by immersing a cationicpolymer in the substrate or coating the substrate with a cationicpolymer, or applying inorganic fine particles capable of adsorbing acolor in an ink such as a porous silica, an alumina sol, and a specificceramic together with a hydrophilic polymer such as polyvinyl alcohol,polyvinyl pyrrolidone and the like on a surface of the substrate. Asheet having an ink receiving layer is generally called as ink-jetexclusive papers (films) or glossy papers (films). For example, thesesheets are commercially available as Pictorico (Asahi Glass Co., Ltd.),Color BJ Paper and Color BJ Photo film sheet (both Canon Inc.), ColorImage Jet Paper (Sharp Corporation), Superfine exclusive glossy film(Epson Corporation), Pictafine (Hitachi Maxell, Ltd.) and the like. Ofcourse, the ink-jet recording method of the present invention can beapplied to plain papers.

[0046] The fibers are preferably polyamide fibers such as nylon, silk,and wool. Woven or non-woven fabric is preferable. The ink compositionof the present invention is applied to the fibers preferably by anink-jet recording method and then fixed under a wet heat condition (forexample, about 80 to 120° C.) or a dry heat condition (for example,about 150 to 180° C.) so that the color can be fixed within the fibers.The thus-dyed product is excellent in clarity, light resistance andlaundry resistance.

[0047] In order to record on a recording material by the ink-jetrecording method of the present invention, for example a containercontaining the above water-based magenta ink composition may be set(filled up) in an ink-jet printer and then the recording may be made onthe substrate according to the conventional method. Example of anink-jet printer includes a piezo-type printer where a mechanicalvibration is employed, a bubble jet (R) type printer where bubblesproduced by heating is employed; and the like.

[0048] In the ink-jet recording method of the present invention, thewater-based magenta ink composition of the present invention may becombined with a yellow ink composition, a cyan ink composition andoptionally a black ink composition. When a water-based cyan inkcomposition comprising a water-soluble metal phthalocyanine color isused as a cyan ink composition, a change in color tone before and aftera light resistance test becomes small by combining it with thewater-based magenta ink composition of the present invention. Example ofa metal in a water-soluble metal phthalocyanine coloring matter includescupper, nickel, aluminum and the like, among which cupper is preferable.Example of a water-soluble cupper phthalocyanine coloring matterincludes C.I. Direct Blue 86, C.I. Direct Blue 87, C.I. Direct Blue 199,C.I. Acid Blue 249, C.I. Reactive Blue 7, C.I. Reactive Blue 15, C.I.Reactive Blue 21, C.I. Reactive Blue 71 and the like.

[0049] A water-based cyan ink composition comprising a water-solublemetal phthalocyanine coloring matter is, for example, prepared accordingto the method of preparing the water-based magenta ink composition ofthe present invention and poured into a container, and the container isset in a predetermined position in an ink-jet printer similarly to thecontainer containing the water-based magenta ink composition of thepresent invention.

[0050] The water-based ink composition of the present invention has aclear magenta color, for which a color tone over a wide visible lightrange can be obtained by using it together with other yellow and cyaninks. By using together with yellow, cyanine and black inks excellent inozone resistance, light resistance and water resistance, printsexcellent in light resistance, water resistance and especially ozoneresistance can be obtained.

EXAMPLES

[0051] The present invention will be described by referring to thefollowing examples. All parts and percentages referred to herein are byweight unless otherwise indicated.

Example 1

[0052] (1) Into 210 parts of xylene, 67.5 parts of the compound of theformula (8):

[0053] 1.4 part of sodium carbonate and 67.2 parts of ethylbenzoylacetate were successively charged and heated. They were reactedat a temperature of 140 to 143° C. for 4 hours, while water and ethanolproduced were distilled away together with xylene. After the reactionwas completed, the resultant product was cooled with water, to which 175parts of methanol was added, stirred for 30 minutes, filtered, washedwith 400 parts of methanol and hot water successively and dried, thereby76.1 parts of the compound of the formula (9) was obtained asneedle-like crystals of a red color.

[0054] (2) To 142.3 parts of 96.6% sulfuric acid was added 207.7 partsof 30.6% fuming sulfuric acid while cooling with an iced water toprepare 350 parts of 12% fuming sulfuric acid. Then, 42.7 parts of thecompound of the formula (9) obtained in the above (1) was added tofuming sulfuric acid at 20 to 40° C. over 30 minutes. Then, they wereheated at 60 to 70° C. for two hours with stirring to complete thesulfonation. Next, the above reaction liquid was added in an iced waterin such an amount that a total liquid volume was 1000 parts. Thereaction was filtered to remove a minor amount of insoluble matter. 200parts of sodium chloride was added to the mother liquid while stirringand they were stirred for one hour. The resultant precipitates werefiltered and washed with 50 parts of a water-based 20% brine solution toobtain a wet cake.

[0055] This cake was again stirred with water in such an amount that atotal liquid volume was 1000 parts. 200 parts of sodium chloride wasadded to the liquid and then stirred for 3 hours. The resultantprecipitates were filtered, washed with 100 parts of a water-based 20%brine solution and dried, thereby 65.0 parts of a sodium salt of thecompound of the formula (4) as crystals of a bright red color.

λ_(max)=528.2 nm (in aqueous solution)

[0056] solubility in water=100 g/L or higher

Example 2

[0057] (1) Into 180 parts of xylene, 43.4 parts of the compound of theformula (10):

[0058] 0.9 part of sodium carbonate and 43.3 parts of ethylbenzoylacetate were successively charged and heated. They were reactedat a temperature of 138 to 141° C. for 6 hours, while water and ethanolproduced were distilled away together with xylene. After the reactionwas completed, the resultant product was cooled with water, to which 200parts of methanol was added, stirred for 30 minutes, filtered, washedwith 250 parts of methanol and hot water successively and dried, thereby50.3 parts of the compound of the formula (11) was obtained asneedle-like crystals of a yellowish red color.

[0059] (2) To 52.9 parts of 96.6% sulfuric acid was added 47.1 parts of31.7% fuming sulfuric acid while cooling with an iced water to prepare100 parts of 6.5% fuming sulfuric acid. Then, 12.2 parts of the compoundof the formula (11) obtained in the above (1) was added to the fumingsulfuric acid at 15 to 20° C. over one hour. Then, they were heated at15 to 20° C. for two hours with stirring to complete the sulfonation.Next, the above reaction liquid was added in an iced water in such anamount that a total liquid volume was 450 parts. The aqueous liquid washeated, to which 48 parts of sodium chloride was added with stirring atabout 60° C. and they were stirred for one hour. The resultantprecipitates were filtered and washed with 50 parts of an aqueous 20%brine solution to obtain a wet cake.

[0060] This cake was again stirred with water in such an amount that atotal liquid volume was 300 parts. After a minor amount of insolublematter was removed by filtering, 52.5 parts of sodium chloride was addedto the mother liquid while stirring and then stirred for 30 minutes toprecipitate crystals. Further, 17.5 parts of sodium chloride was addedand stirred for 30 minutes. The resultant precipitates were filtered,washed with 50 parts of an aqueous 20% brine solution to obtain 32 partsof a sodium salt of the compound of the formula (5) as a wet cake.

[0061] (3) The wet cake obtained in the above (2) was stirred with 250parts of methanol at room temperature for 30 minutes, filtered, washedwith 200 parts of methanol and dried, thereby 13.3 parts of the compoundof the formula (5) was obtained as crystals of a bright yellowish redcolor.

λ_(max)=531.0 nm (in aqueous solution)

[0062] solubility in water=100 g/L or higher

Example 3

[0063] To 46.3 parts of 96.6% sulfuric acid was added 53.7 parts of31.7% fuming sulfuric acid while cooling with an iced water to prepare100 parts of 10% fuming sulfuric acid. Then, 9.2 parts of the compoundof the formula (11) obtained in Example 2-(1) was added to the fumingsulfuric acid at room temperature over about 30 minutes. Then, they wereheated and reacted at 25 to 30° C. for 1.5 hours. Successively they wereheated and reacted at 60 to 70° C. for 1.5 hours to complete thesulfonation. Next, the above reaction liquid was added in an iced waterin such an amount that a total liquid volume was 300 parts. 60 parts ofsodium chloride was added to the aqueous liquid and they were stirredfor one hour. 600 parts of methanol was added to the aqueous solution toprecipitate crystals. After stirring for one hour, the precipitates werefiltered, washed with 300 parts of methanol and dried, thereby thecompound of the formula (12) was obtained as crystals of a red color.

λ_(max)=529.6 nm (in aqueous solution)

[0064] solubility in water=100 g/L or higher

Example 4

[0065] (1) Into 100 parts of xylene, 26.4 parts of the compound of theformula (13):

[0066] 0.6 part of sodium carbonate and 28.8 parts of ethylbenzoylacetate were successively charged and heated. They were reactedat a temperature of 140 to 143° C. for 4 hours, while water and ethanolproduced were distilled away together with xylene. After the reactionwas completed, the resultant product was cooled with water, to which 150parts of methanol was added, stirred for 30 minutes, filtered, washedwith 200 parts of methanol and hot water successively and dried, thereby33.2 parts of the compound of the formula (14) was obtained asneedle-like crystals of a red color.

[0067] (2) To 39.7 parts of 96.6% sulfuric acid was added 35.3 parts of31.7% fuming sulfuric acid while cooling with an iced water to prepare75 parts of 6.5% fuming sulfuric acid. To fuming sulfuric acid undercooling with ice, 8.5 parts of the compound of the formula (14) obtainedin the above (1) was added at 15 to 20° C. over 15 minutes. Then, theywere reacted at 50 to 60° C. for 2 hours and successively at 70 to 80°C. for 2 hours. Next, the above reaction liquid was added in an icedwater in such an amount that a total liquid volume was 300 parts. 45parts of sodium chloride was added to the aqueous liquid with stirringat room temperature and they were stirred for one hour. The resultantprecipitates were filtered, washed with 50 parts of an aqueous 20% brinesolution and dried, thereby 11 parts of red crystals comprising themixture of 8.8 parts of the compound of the formula (15) and 2.2 partsof the compound of the formula (16).

λ_(max)=527.8 nm (in aqueous solution)

[0068] solubility in water=100 g/L or higher

Example 5

[0069] (A) Preparation of Ink

[0070] A mixture having a composition as shown in the following Table 1was prepared. This mixture was filtered through a membrane filter of0.45 μm, thereby an aqueous ink composition for ink-jet recording of thepresent invention having a pH of 8 to 10 was obtained. TABLE 1Composition amount (parts) coloring matter obtained 3.0 in Ex. 1 water +ammonium hydroxide 78.0 glycerol 5.0 urea 5.0 N-methyl-2-pyrrolidone 4.0IPA 3.0 butyl carbitol 2.0 total 100.0

[0071] (Comparative Compositions)

[0072] For comparison, magenta ink compositions of Comparative Examples1 and 2 were prepared by using C.I. Acid Red 82 (Comparative Example 1)and C.I. Direct Red 227 (Comparative Example 2) and applying thecomposition ratio as shown in Table 1 so that each of the resultantcompositions had an optical density identical with that of thewater-based magenta ink composition of the present invention.

[0073] (B) Ink Jet Printing

[0074] Using an ink-jet printer (trade name: PICTY 100L, NECCorporation), an ink-jet recording was made on a commercially availableexclusive paper (PR-101 of Canon Inc.) and a commercially availableexclusive paper (PM photographic paper of Epson Corporation).

[0075] (C) Evaluation of Recorded Images

[0076] Hue (L*, a* and b* values) and color difference (ΔE*ab) beforeand after each test of the recorded images were determined using acolorimeter (GRETAG SPM 50 of GRETAG). Clarity (C*) of the recordedimages was evaluated according to the following equation:

C*=((a*)²+(b*)²)^(1/2)

[0077] (i) Light Resistance Test

[0078] The resultant print was exposed for 20 hours using a carbon arcfade meter (Suga Test Instruments Co., Ltd.). A change before and afterthe exposure was judged in accordance with JIS blue scale.Simultaneously, a color difference before and after the exposure wasdetermined using the above calorimeter.

[0079] (ii) Ozone Resistance Test

[0080] The resultant print was treated under conditions of aconcentration of 4 ppm and a temperature of 40° C. for 20 hours using anozone weather meter (Suga Test Instruments Co., Ltd.). A colordifference before and after the treatment was determined using the abovecalorimeter.

[0081] The results of the recorded images with respect to hue, clarity,difference in clarity (ΔC*), light resistance test and ozone resistancetest are shown in Table 1. The difference in clarity (ΔC*) is a valuewith reference to the hue resulting from the magenta ink composition ofthe present invention.

[0082] The evaluation results of the images recorded on the exclusivepaper (PR-101 of Canon Inc.) are shown in Table 2. The evaluationresults of the images recorded on the exclusive paper (PM photographicpaper of Epson Corporation) are shown in Table 3.

[0083] In the following tables, M1 represents the ink composition ofExample 5, M2 represents the ink composition of Comparative Example 1and M3 represents the ink composition of Comparative Example 2. TABLE 2Evaluation results on exclusive paper (PR-101 of Canon Inc.) ozone lighthue clarity resistance resistance L* a* b* C* ΔC* ΔE*ab judgement ΔE*abM1 53.6 76.4 −3.26 76.5 ref 1.13 3-4 8.4 Grade M2 54.1 73.5 3.47 73.6−3.8 13.80 4 3.4 Grade M3 54.8 75.3 −4.63 74.5 −2.0 12.00 2 33.9 Grade

[0084] TABLE 3 Evaluation results on exclusive paper (PM photographicpaper of Epson Corporation) ozone resis- light hue clarity tanceresistance L* a* b* C* ΔC* ΔE*ab judgement ΔE*ab M1 53.8 77.1 −4.95 77.3ref 2.82 3-4 9.6 Grade M2 54.7 73.3 −0.56 73.3 −4.0 11.21 4 2.9 Grade M351.3 75.8 −10.74 76.5 −0.8 14.32 2 47.8 Grade

[0085] As clear from Tables 2 and 3, the magenta ink composition of thepresent invention is superior, especially in ozone resistance, ascompared with the magenta ink compositions of Comparative Examples land2. Thus, the magenta ink composition of the present invention is veryuseful as a magenta ink giving prints excellent in long-period storagesince prints resulting from the use of the magenta ink composition ofthe present invention are hardly affected by light and components suchas gases contained in an air even if they are stored or displayed for along period.

[0086] As clear from Tables 2 and 3, the ink composition of the presentinvention has an almost ideal magenta color as compared with C.I. AcidRed 82 of the anthrapyridone color used in Comparative Example 1 sinceit gives a clear purple color having a good hue and clarity. And, it canbe said that the ink composition of the present invention is verysuperior ink composition since C* value is higher and clarity is better.

[0087] As clear from Tables 2 and 3, the ink composition of the presentinvention has higher light resistance as compared with C.I. Direct Red227 of Comparative Example 2 which is presently used as a magentacomponent in ink-jet inks. Therefore, prints resulting from the use ofthe ink composition of the present invention can be stored for a longperiod. Since the compound of the present invention has a solubility inwater of 100 g/L or higher, it is very excellent as a coloring matterfor ink-jet recording and an ink with a high concentration can beprepared.

[0088] Effect of the Invention

[0089] The anthrapyridone compound and the magenta ink compositioncontaining it according to the present invention have characteristicthat they have a high solubility in water so that they aresatisfactorily filtered through a membrane filter during the preparationof an ink composition. And, the anthrapyridone compound is very safe forliving body. Further, the ink composition of the present invention hasgood storage stability and therefore, it does not cause precipitation,change in physiological properties, color change and the like even afterstored for a long period. Since prints resulting from the use of the inkcomposition of the present invention as a magenta ink for ink-jetrecording is excellent in light resistance, moisture resistance andespecially ozone resistance, it is possible to use together with yellow,cyan and black colors so that each color excellent in ozone resistance,light resistance and water resistance can be obtained by an ink-jetrecording method. Especially this advantage is remarkably exhibited on arecording paper having an ink receiving layer. In addition, theresultant printed surface has a clear magenta color close to an idealmagenta color so that a color tone over a wide visible light range canbe obtained by combining with other yellow and cyan inks. Accordingly,the anthrapyridone compound of the present invention is very useful as acolor in a magenta ink for ink-jet recording.

What is claimed is:
 1. An anthrapyridone compound represented by theformula (1):

wherein R represents hydrogen atom or methyl group; X represents phenylgroup, phenoxy group or halogen atom; and n is an integer of 1 to 4, ora salt thereof.
 2. The anthrapyridone according to claim 1, wherein n isan integer of 2 to 4, or the salt thereof.
 3. The anthrapyridonecompound according to claim 2, wherein X represents phenyl group, or thesalt thereof.
 4. An anthrapyridone compound represented by the formula(2):

wherein X represents phenyl group, phenoxy group or halogen atom, or asalt thereof.
 5. An anthrapyridone compound represented by the formula(3):

wherein X represents phenyl group, phenoxy group or halogen atom, or asalt thereof.
 6. An anthrapyridone compound represented by the formula(4):

or a salt thereof.
 7. A water-based magenta ink composition comprisingthe anthrapyridone compound as defined in any one of claims 1 to 6, orthe salt thereof.
 8. The water-based magenta ink composition accordingto claim 7 comprising water and a water-soluble organic solvent.
 9. Awater-based magenta ink composition according to claim 7 or 8, whereinsaid composition is for ink-jet recording.
 10. An ink-jet recordingmethod, which comprises using the water-based magenta ink compositionaccording to any one of claims 7 to 9 as the ink in the ink-jetrecording way that ink droplets are jetted responding to recordingsignal to record on a recording material.
 11. An ink-jet recordingmethod, which comprises using the water-based magenta ink compositionaccording to any one of claims 7 to 9 as the ink and a water-based cyanink composition comprising a water-soluble metal phthalocyanine coloringmatter as a cyan ink in the ink-jet recording way that ink droplets arejetted responding to recording signal to record on a recording material.12. An ink-jet recording method as defined in claim 10 or 11 wherein thesubstrate to be recorded is a polyamide fibrous material and the fibrousmaterial is heat treated after the ink composition is applied.
 13. Anink-jet recording method according to claim 10 or 11 wherein therecording material is an information transmittance sheet.
 14. An ink-jetrecording method according to claim 13 wherein the informationtransmittance sheet is a surface treated sheet.
 15. An ink-jet printerin which a container containing a water-based magenta ink compositionaccording to any one of claims 7 to 9 and a container containing awater-based cyan ink composition comprising a water-soluble metalphthalocyanine coloring matter are set.